1. Field of the invention
This invention relates to an electrical connection element used as a connection terminal in a connector for making an electrical connection to electrical equipment or in a junction connector, and more particularly to an electrical connection element which is prevented from plastic deformation due to interference with a mating terminal with which it is electrically connected, and can provide a good contact load.
2. Related art
A conventional electrical connection element of the common type will now be described with reference to FIGS. 8 to 10. As shown in FIG. 8, the electrical connection element 1 is one called a female terminal, and includes a longitudinal outer wall portion 2, a resilient connecting portion 4 formed by folding back a metal base plate 3, and a pair of flexure prevention pieces 5a and 5b. These constituent elements are formed integrally by working the single metal base plate 3.
As shown in FIG. 9, the resilient connecting portion 4 is slanting upwardly as viewed from a direction A of insertion of a male terminal 6, and when the male terminal 6 is inserted, the connecting portion 4 is deformed downwardly as shown in FIG. 10. However, since first and second folded portions 7a and 7b are so folded as to be resiliently deformable, the male terminal 6 can be inserted with a low resistance, and the resilient connecting portion 4 resiliently contacts the male terminal 6 over a wide area, thus making a good electrical connection.
When the resilient connecting portion 4 is deformed as shown in FIG. 10, the flexure prevention pieces 5a and 5b engage the back side of the resilient connecting portion 4 to limit the deformation, thus preventing plastic deformation. To achieve this, the flexure prevention pieces 5a and 5b are stamped out to project inwardly respectively from opposite side walls 2a and 2b of the outer wall portion 2, and are extended into the resilient connecting portion 4 in perpendicular relation to the opposite side walls 2a and 2b.
Incidentally, the connection construction of the above electrical connection element is disclosed in Japanese Utility Model Unexamined Publication Nos. 55-14230, 55-36528, 58-62564, 1-115174 and 1-168969.
The outer wall portion 2 is formed by bending after the resilient connecting portion 4 is formed by the metal base plate 3. If the flexure prevention pieces 5a and 5b, formed respectively on the opposite side walls 2a and 2b, are made long, these pieces interfere with the bending of the outer wall portion 2, and therefore they can not be made long. For this reason, in the assembled condition shown in FIG. 8, the flexure prevention pieces 5a and 5b can not be sufficiently extended in facing relation to the back side of the resilient connecting portion 4. Therefore, when the resilient connecting portion 4 is flexed and deformed as shown in FIG. 10, part of the resilient connecting portion 4, that is, opposite side portions of the resilient connecting portion 4, engage the flexure prevention pieces 5a and 5b, respectively, and therefore the amount of flexing of the resilient connecting portion 4 has been liable to vary.
The flexure prevention pieces 5a and 5b must be formed short because of the above-mentioned working limitation; however, it is difficult to obtain satisfactory dimensional accuracies of such stamped-out portions. Further, the dimensions of the flexure prevention pieces 5a and 5b are also influenced by the accuracy of bending of the outer wall portion 2, and therefore the opposite side walls 2a and 2b must be parallel to each other.
As described above, in the above conventional electrical connection element 1, because of the workability of the flexure prevention pieces, such as their length, and also because of an insufficient face-to-face contact of the resilient connecting portion with the flexure prevention pieces, there has been encountered a problem that a stable flexure prevention function and others can not be achieved.